Graphite film is a material having excellent properties such as high thermal conductivity, and is therefore widely used in electronic parts and the like. Examples of a method for producing a commonly-available high thermal conductive graphite film include an expanding method in which exfoliated graphite is rolled into a sheet and a polymer pyrolysis method.
For example, a graphite film production method has been disclosed, in which a polymer film is wound around a graphitic carbon cylinder, more specifically, a laminate of three sheets of POD film having a width of 180 mm and a thickness of 50 μm is wound around a graphitic carbon cylinder having an outer diameter of 68 mm, an inner diameter of 64 mm, and a length of 200 mm and heated at 1800° C. or higher in an inert gas or in a vacuum to obtain an elongated graphite film. (Patent Document 1)